Transducers which make use of the Hall effect (a phenomenon that results in a voltage across a current-carrying element that is representative of a magnetic field transverse to the current) are common. These “Hall effect sensors” are integrated into a wide range of devices, from GPS trackers and cell phones to fluid flow monitors and rotational motion sensors. The electron mobility and electron hole mobility of the current-carrying element affects the sensitivity of the Hall effect sensor, with greater electron hole mobility in particular resulting in a more sensitive Hall effect sensor.
Hall effect transducers built into semiconductor wafers are common. These transducers typically involve a symmetrically electrically contacted plate or layer of a semiconducting material (a Hall plate) through which current is passed and across which voltage is monitored. Hall plates built into semiconductor wafers have traditionally been constructed of silicon.